Spectrum is a multipurpose tool specifically designed for ultrasonic applications. It has a flexible user interface developed specifically for processing ultrasonic signals. Data capture from oscilloscopes, and several data simulations are built into the software, providing an environment to quickly and easily acquire and process signals to maximise productivity.

Spectrum Download

Summary of features


  • Intuitive user interface.
  • Unlimited undo-redo capability.
  • Data copy for export via clipboard as EMF and CSV text formats.


  • Multilayer plate response (frequency domain).
  • Transducer response (frequency domain).
  • Waveform generation (time domain).

Data capture

  • Waveforms captured from oscilloscopes via GPIB interface.
  • In-built communication for Lecroy 9400, 9310 scopes.
  • Single or dual channel manual or timed capture.
  • Smart autosave and average handling capability.

Viewing data

  • Waveform or contour plotting.
  • Layers palette to control display of multiple waveforms in a single document.
  • Multiple waveforms can be gathered into a single layer for 2D signal processing.

Signal processing

  • 1D and 2D FFT.
  • Time domain gating.
  • Frequency domain filtering
  • Hilbert envelope
  • Convolution, division, addition and subtraction of waveforms.

Data handling

  • Multiple data set import from Winspect, Abaqus, Finel software.
  • Data copy for export via clipboard as EMF and CSV text formats.

Multilayer plate response simulation

The in-built tool to simulate the response from a multilayer plate system is a particularly useful modelling tool. A summary of its capabilities is given below:


  • Generation of frequency or angular spectral response of multilayer plates.
  • User friendly wizard for definition of multilayer systems and simulation parameters.
  • Fast global matrix solution algorithm.
  • Details of previous simulations are retained to allow parametric studies to be carried out rapidly.
  • Multilayer system can be easily defined and remembers the last definition to simplify parametric studies.
  • Isotropic materials can be defined by wave velocities or elastic properties, and stored in a library.
  • Choice of incoming longitudinal or shear wave.
  • Frequency or angular domain spectra can be generated.
  • Infinite plane wave transducer used to generate angular spectra.
  • Choice of infinite plane wave transducers, or finite transducers of definable width, for the generation of frequency spectra.
  • Flexible, transducer geometry arrangement for frequency simulations.
  • Longitudinal and shear reflection and transmission coefficient spectra can be generated for infinite transducer models.
  • Results can be convolved with simulated transducer responses, and transformed via an FFT to give a time domain response.


  • Angular spectra can show the critical angle for mode conversion between longitudinal and shear waves.
  • Frequency spectra can highlight resonant frequencies and the detectability of the resonances in the multilayer system.
  • Predicted time domain signals, obtained by convolution with a transducer response and transformation to the time domain, can be used to optimise an experimental setup.
  • Parametric studies of the material system, attenuation and thickness variation in adhesives for example, can greatly assist in designing ultrasonic tests.

Software download

Spectrum is available for download without charge.
Register to download now.

Any feedback or bug reports would be welcomed. Although we are unable to provide support free of charge, we will endeavour to correct any bugs and notify you when an updated version becomes available.

System requirements

To run Spectrum you will need a modern PC running Microsoft Windows 98, ME, NT, 2000, or XP. Note, Spectrum will not run on Windows 95.

Further Information

All questions and comments should be addressed to the authors:

Dr Jonathan Allin

Prof. Mike Lowe 
NDE Lab 
Department of Mechanical Engineering 
Imperial College 
Exhibition Road 
London SW7 2BX 
Tel: +44 (0) 20 7594 7071 
Fax: +44 (0) 20 7584 156